Power take-off lockout mechanism



Feb. 6, 1945. G. D. SHAEFFER 2,369,078

POWER TAKE-OFF LOCK-OUT MECHANISM Filed Feb. 27, 1943 5 Sheets-Sheet 1 INVENTOR B Y #l 44 g, Y/M44. ATTORNEY Pei)? 1945- G. D. SHAEFFElR 2,369,078

POWER TAKE-OFF LOCK-OUT MECHANISM Filed Feb. 27, 1943 5 Sheets-Sheet 3 INVENTOR ATTORNEYS.

Patented Feb. 6, 1945 2,369,078 POWERTAKE-OFF LOCKOUT MECHANISM George D. Shaefler, Detroit, Mich, assignor to Gar Wood Industries, Inc., Detroit, Mich., a corporation of Michigan Application February 27, 1943, Serial No. 477,393

4 Claims.

The present invention rel-ates to a lock-out mechanism for a power take-off on a vehicle.

One of the primary objects of the present invention is to provide a lock-out mechanism for a power take-01f on a vehicle where such lockout mechanism is associated with the vehicle gearshift lever and is movable therewith so that the power take-off cannot be thrown in except in a selected position of the gear shift lever.

A further object of the invention is to provide a lock-out mechanism of the type mentioned which is so constructed and associated with the gear shift lever that the power takeoff can only be thrown in when the gear shift lever is in first or low speed position.-

A more specific object of the present invention is to provide a lock-out mechanism between an hydraulic pump and a variable speed transmission so that the pump can only be operated at low speed, thereby preventing its burning out at the higher speeds and cannot be rotated in a reverse rotation.

Other objects of the invention will become apparent from the following description, from the drawings forming a part of the specification, and from the claims hereinafter set forth.

For a better understanding of the invention, reference may be had to the drawings, wherein:

Figure 1 is a partial perspective view of the interior of an automotive vehicle showing the lock-out mechanism of the present invention associated with the power take-off and a power unit, such as an hydraulic pump;

Figure 2 is a, fragmentary, side elevational view of a portion of the structure shown in Figure 1;

Figure 3 is a top plan view taken substantially I along the line 33 of Figure 2;

Figure 5 is a vertical cross-sectional view'of lever when the gears are in first, second, third, and reverse, respectively.

A power take-off mechanism, generally indicated at 28, is provided which includes a housing 00 having a removable end plate within which the transfer gears are mounted. Such gears include an internal gear 92 adapted to be connected to a variable speed transmission in a mannerto bedescribed in detail hereinafter. Such gear 92 is connected to a shaft 04 which is mounted within suitable bearings within-a bore provided in the housing 90. An external gear 96 is disposed within the housing and is connected with the opposite end of the shaft 94, to be driven thereby. The gear 98 meshes with an idler gear 90 which is rotatablymounted on a shaft IOI. ,Such shaft IN is mounted within aligned trunniqns provided in the housing 90. The gears 98 and 98 are in constant mesh and the gear 98 is adapted to mesh with a gear I02 which is splined to a spline shaft I04. The spline shaft I04 is mounted within'suitable bearings I00 which are in turn mounted within the housing 90, and one end of the shaft I04 projects outwardly of the housing and has a couplingjfll connected thereto which is adapted to be connected to the drive shaft of a power element, such as an hydraulic pump.

By shifting the gear I02 along the shaft I04, the gear I02 may be thrown in or out of mesh with the gear 98 to drive the shaft I04 or to have it remain idle. The gear I02, is shifted by a movable actuating element 32 which is connected to the gear I02 by means of a yoke arm IIO which is mounted on the inner end of element 32. The prong of such arm is received within an annular groove II2 formed integral with the gear I02 which projects outwardly of the housing of the power take-off. When such element 32 is moved to the right, viewing Figure 2, the power take-oil is thrown in; and when the element 32 is moved to the left, viewing Figure 2, the power take-off is thrown out. The element 32 may be held in either of its positions by means of a spring pressed detent II4 which engages within either one ofv longitudinally spaced grooves H0 or H8.

, In order to shift the movable member,

a lever 34 is pivotally mounted to a bracket 36 by means of a pivot pin 38 in a, position adjacent the side of the seat I4. The lower end to a plate member 44 by means of a pivot pin 46.,

1 return the fluid-to the tank l2. 1 and 82 may be operatively connected to hydraulic The plate member 44 is fixedly secured to the .forward end of the actuating element 32. Thus,

when the upper end of the lever 34 is moved forwardly, the plate 44 is moved rearwardly to throw the power take-off out, and when the upper end of the lever 34 is pulled rearwardly the power take-oil is thrown 'in.

According to the present invention, lock-out mechanism generally indicated at 58 is associated with the actuating element 32 and the gear shift lever' I8 so that the power take-off can only be thrown in when the gear shift lever I8 is in first or low gear. Such lock-out mechanism 58 includes a plate member 52 which is bent substantlally at right angles to provide an upper substantially horizontalportion 54 and a lower substantially horizontal portion 56. The portion 54 is pivotally connected to an upstanding bracket 58 mountedon the vehicle floor adjacent. the gear shift lever by means of a pivot pin 58.

The portion 54 is formed with a slot 82 inthe .end thereof which is adapted to embrace the gear shift lever I8 so that such lever slidably engages the sides of the slot as it is shifted to its various positions. The portion 58 is formed with a stop edge 64 having a limit stop projection at one end thereof and such stop edge is so constructed that as the member 52 is pivoted about pivot 68 when the gear shift lever I8 is shifted, the edge 84. is positioned to block movement toward the .right, viewing Figure 2, of actuating element 32 for certain positions of the gear shift lever. In particular, the movement of the actuating element 32 will be blocked when the ,gearshift lever I8 is in its neutral position or moved to positions 22, 24, and 28, as shownin Figure 3. However, when the gear shift lever I8 is moved to position 28, which is the first or low gear position of the gear shift lever, the plate 52 is pivoted so that the edge 84 is moved out of blocking position with respect to the actuating element 32 so that it may be moved to the right, viewing-Figure 2, as shown in Figure 4. As stated above. in this position the power take-off is then thrown in so that power may then be transmitted through the take-off 28 to suitable operating elements. In this position it may be stated also that the gear shift lever a variable speed transmission, generally indicated at I28. Such transmission I28 may be of any of the conventional types with three speeds forward and reverse, or four speeds forward and reverse,

for example, or any of the conventional types.

toward gear I38 is in direct mesh therewith for driving at high speed. When gear I34 is shifted to mesh with gear I29 the drive is in second or intermediate speed. Gear I38 is mounted on the splineshaft, and when shifted to mesh with gear I3I the drive is in first or low speed. The usual idler gear I35 is mounted within the housing I22 behind the counter-shaft and is constantly drivan by gear I3I. When gear I36 is shifted to mesh with idler I35 the drive is in reverse. The transmission structure is conventional, as mentioned above, and is shown here merely for the purpose of illustration in that a variable speed transmission has particular significance in the combination here disclosed.

The shaft I24 projects rearwardly out of the housing I22 and is adapted to be connected to the propeller shaft in the usual way. The power take-off 28 is transversely offset with respect to the propeller shaft so there will be no interference with it. In order to transfer the drive from shaft I24 to the power take-off I28, a gear I48 is keyed to the outwardly projecting end of the 40 shaft I24 and is adapted to mesh with another I8 is in a locked position and cannot be shifted j V speeds, including forward and reverse, and while Iuntil after lever 34 has been returned to its former position.

In the embodiment illustrated, .the power takeoff 28 is operatively connected to andadapted to drive a conventional hydraulic gear pump I8.

The hydraulic fluid, preferably oil, is supplied to the pump from a tank or reservoir I2 through an pump I8. The pressure outlet from the pump I8 leads to the inlet of a conventional four-way spool valve I8. The spool of the valve 18 is shifted to its various positions by means of an operating lever 18 and when in one .position the fluid inlet conduit I4 associated with the inlet of the v conduit 88 and returns through conduit 82. An-

other conduit 84 is associated with the valve to The conduits 88 Jacks for the purpose of operating bulldozer or scraper elements as may be desired. The stop mechanism of the present invention has particular utility when combined with an hydraulic pump and power take-off because of the danger can only be operated at low speed.

The power take-ofi 28 receives its power from gear mounted on the shaft I42. The shaft I42 and gear which meshes with gear I48 may all be enclosed within a suitable gear box I44. The shaft I42 has an external gear I48 secured to or formed integral with the end thereof which is adapted to be received within and mesh with the internal gear 92 of the power take-off.

While the transmission may operate at various such speeds and direction of speeds are transmittted directly to the power take-off, it will be understood from the above that the gear I82 can only mesh with the gear 98 when the transmission is shifted to its low or first speed.

According to the above, a construction is provided whereby the pump I8 may be operated only when the gear shift lever I8 is in first or low gear.

What is claimed is: g

1. A lock-out mechanism for a power take-off on a vehicle having a gear shift lever movable to any one of a plurality of positions, and in which said power take-off has a movable actuating element, comprising a pivoted stop element, means pivotally mounting said stop element, said stop element having an elongated slot adapted to em brace said lever so that when said lever is moved to any of said positions said stop element is correspondingly pivoted and a stop portion on said stop element so constructed as to block the movement of said actuating element in certain positions of said lever and to permit the movement of said actuating element in a particular one position of said lever.

2. A lock-out mechanism for a power take-ofl on a vehicle having a gear shift lever movable to any one of a plurality of positions, and in which said power take-oi! has a. movable actuating element, comprising a pivoted stop element, means pivotally mounting said stop element intermediate-the ends thereof, said stop element having an elongated slot formed in one end thereof adapted to embrace said lever so that when said lever is moved to any of said positions said stop element is correspondingly pivoted, and a stop portion on the opposite end of said stop element so constructed as to block the movement of said actuating element in certain positions of said lever and to permit the movement 01' said actuating element in a particular one position of said lever.

3. A lock-out mechanism for a power take-oi! on a vehicle having a gear shift lever movable to first, second, third and reverse positions, and in which said power take-oi! has a movable actuating element, comprising a pivoted stop element, means pivotally mounting said stop element, said stop element having an elongated slot adapted to embrace said lever so that when said lever is moved to any of said positions said stop element is correspondingly pivoted, and a stop portion on said stop element so constructed as to block the movement of said actuating element in said second, third and reverse positions of said lever and to permit the movement of said actuating element in said first position oi. said lever.

4. A lock-out mechanism for a power take-oi! on a vehicle having a gear shift lever movable to any one of a plurality of positions, and in which said power take-oil has a movable actuating element, comprising a pivoted stop element, means pivotally mounting said stop element, said stop element being connectable with said lever so that when said lever is moved to any of said positions said stop element is correspondingly pivoted and a stop portion on said stop element so constructed as to block the movement 01' said actuating element in every position of said lever except one, said actuating element being disposed against a portion of said stop element when in said one position to prevent pivoting of said stop element until said actuating element is released, is thereby preventing shifting of said gear shift lever until said actuating element is moved to its released position.

GEORGE D. SHAEFFER. 

